Preparation of magnetic β-cyclodextrin ionic liquid composite material with different ionic liquid functional group substitution contents and evaluation of adsorption performance for anionic dyes

Abstract

In this study, we successfully prepared two magnetic graphene oxide composites, specifically (mGO@ILs(1)-βCD and mGO@ILs(2)-βCD), with different ionic liquid functional group substitution contents on the β-cyclodextrin (β-CD). Structural characterization of the composite material was performed using Fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy, specific surface area and pore volume measurements. Comparison of the adsorption performance of the two materials for anionic dyes (lemon yellow (LY), sunset yellow (SY), and ponceau 4R (P4R)) in simulated wastewater. Effect of initial pH value, contact time were studied and discussed in terms of affinity and adsorption efficiency. The adsorption of the anionic azo dye by two adsorbent followed Langmuir adsorption isotherm models and pseudo-second-order kinetics. Noticeably, the maximum adsorption capacity based on the Langmuir model showed that mGO@ILs(2)-βCD was better than mGO@ILs(1)-βCD. Additionally, the adsorbent maintains excellent adsorption capacity after five cycles of adsorption-desorption and has remarkable selective separability. The results showed that the high-density substitution content of the ionic liquid functional groups on β-cyclodextrin in mGO@ILs(2)-βCD is helpful to improve the adsorption capacity and efficiency.